well, the center of buoyancy is the centroid of the volume displaced by the hull. The weight of that volume of water is equal to the total weight acting on it (or else you are no longer floating). When you speak of center of gravity, you mean the centroid of all of those weights that cause the displacement (weight of boat, human, cooler of beer, etc). They will always work themselves to being equal longitudinally and transversely (until it is no longer possible and the boat capsizes), but never vertically (unless I suppose you had concrete blocks roped to the bottom of the hull pulling downward)..

: uhmm, when you get your underwater section isnt the center of buoyancy and
: gravity the same thing?